Apparatus for use in the treatment of strips of photographic film



F. J. M. HANSEN APPARATUS FOR USE IN THE TREATMENT OF STRIPS OF PHOTOGRAPHIC FILM Filed March 6, 1922 I 7211672Zb) Frzkdriciz {Mia/wen 1 TAZZZW'MyJI Patented Feb. 17, 1925.

UNITED STATES- PATENT OFFICE.

FRIEDRICH JACOB MARTIN HANSEN, F COLOGNE, GERMANY, ASSIGNOR T0 ROBERT ROSENTHAL, OF BASEL, SWITZERLAND.

APPARATUS FOR USE IN THE TREATIYLENT 0F STRIPS OF PHOTOGRAPHIC FILM.

Application filed March 6, 1922. Serial No. 541,554.

fihns, hereinafter referred to as films, ditficulties are met with in connection with the means for moving the film during its pas sage through the baths in consequence of the difi'erent degrees of extension of the film in the various baths it has to traverse-in succession. In some forms it is also necessary to impart a twist to the film so that the blank or uncoated side alone comes in contact with the guide rollers.

In apparatus of this kind in which the separate baths to be traversed by the film are contained in tubes, the idea would readily suggest itself that the film should be driven by means of a roller situated above said tube. Experiment, however, has shown that this is not unconditionally practicable, since, for the reason already mentioned the film must be twisted inside the tubes, and there is consequently an unequal pull on the roller.

The object of the present invention is to impart motion to the film in order to pass it through the various baths so as to obviate the above difficulties. This is accomplished by driving 'the film through the different baths, by means of a smooth roller so arranged that any unequal tension of the film is counteracted by its slip on the roller. According to this invention, this is effected by operating the roller intermittently and by arranging that the adhesion between the film and the surface of the roller is so small that differences of tension in the film are equalized in its passage over the roller.

The accompanying drawing, which is more or less diagrammatic, illustrates an example of a developing apparatus according to this invention. Fig. 1 1s a front ele- 'vation, and Fig. 2 a side elevation of the machine. The exposed film F is passed from a receptacle 1 into the first tube 2, which contains the developer. In the bottom of this tubeis a roller or uide device round which the film is passed so that the film passes first downwards and then upwards in the tube. On leaving the developing tube. the fihn is passed over the driving roller from which it receives motion in the manner described below, and is then passed, in a similar manner, into the fixing tube i. After leaving the fixing tube it is again passed over the driving roller 3, which imparts a driving motion to it. The operation proceeds in the same manner in the washing tube 5 in which the film is washed, and whence it is again passed over the driving roller 3 and into the staining tube 6 containing a solution of aniline dye. From the tube 6 the film is led over a drum 7, which faced with soft rubber in order to obtain greater adhesion. The roller 7 is of larger diameter than the driving roller 3 and is connected therewith by means of a clutch :5. This clutch may be of a simple friction type, and is so arranged that the roller 7 is rotated indirectly by the roller 3 through the said clutch. This friction clutch, in combination with the roller T, is of special importance to the success of the whole arrangement. Since the diameter of the roller 7 is larger than that of the driving roller it tends to impart a higher velocity to the fihn than is transmitted to the latter by the driving roller 3 after it issues from each of the tubes; but since the roller T is only operated by a friction clutch, said roller can only exert tension on the film to the extent permitted by the friction clutch. In consequence of this operation, the film is maintained at a tension corresponding to the adjustment of the clutch. Since, according to the invention, the driving roller 3 is such that a slight degree of adhesion exists between the film andithe roller, the tension imparted to the film by the roller '7 is distributed uniformly through all the tubes. Another point of special importance is that the roller is driven intermittently, and not continuously, a method which ofiers the advantage, in connection with the uniform distribution of tension on the film, that the film receives an acceleration of motion at the various operating points on the driving roller, but then has time for the tension to become equalized during the intervals of repose. Moreover, the intermittent drive offers the further advantage in connection with the film that it on the reduced end ,of the roller 3,'while its other end is connected to and operatedbya crank or 'anJeccentric 12 which is rotated by an electromotor 13. A pawl 14: serves to prevent backward rotation.

After the film has been passed through the various tubes or baths in the manner described itpasses over the roller 7 apparatus in order to be dried. I It is immaterial tothe spirit of the invention whether the film is passed through a plurality of separate tubes or containers charged with the same or different baths, or

whether the same method of drive is applied to a single tank through which the film is passed to and fro. Neither is this invention limited to any particular number of tubes or compartments oikkind of liquids contained therein.

What I claim "and desire to Letters Patent is 1. Apparatus for use in treating strips of photographic film in which the progressive movement of the film through one or more baths is effected by means of an intermittently operated roller'over which the film is passed in the form of loops, said roller having a smooth surface so that the adhesion protect by between the film and the roller enables differences of tension on or lengthening of the film to be equalized by the slip of the strip of film on the roller.

2. An apparatus for use in treating strips, of photographic film comprising a series of liquid receptacles, a smooth surface roller arranged horizontally over the receptacles and a rubber or other adhesive covering for that part of the roller which is over the last receptacle and means for rotating the roller intermittently. v

3. An apparatus for use in treating strips of photographic film comprising a series of liquid receptacles, a smooth surface roller out of the h arranged horizontally over the receptacles, a drum loosely mounted on said roller, a fric tional covering-for said drum, a clutch connected between the roller and drum and means for rotating the roller intermittently. 4. Apparatus for use in treating strips of photographic film comprising a series of 0011- tainers for developer and other liquid through which the film is to be passed, .film guide devices in the bot-tom of the containers,

a common smooth surfaced driving roller .over which the strip of film is passed between each container and a, frictional ten- ,sion device acting on the film as it passes through the apparatus for the purpose described and means for rotating the roller intermittently.

Anapparatus for use in treating strips of photographic film in which the progressive movementof the film through one or more baths is effected by means of a roller over which the film is passed in the form of loops, the said roller having a smooth surface so" that the adhesion between the film and the roller enables differences of tension on or the lengthening of the film to be equalized by the slip of the strip OI film on the roller, and means for rotating the roller.

6. An apparatus for use in treating strips of photographic film comprising a series of liquid receptacles, a smooth surface roller arranged horizontally over the receptacles, a drum loosely mounted on said roller, a clutch connecting said drum and roller, and means for intermittently rotating the roller.

7. An apparatus of the type described for use in treating a strip of photographic film comprising a roller over which the film to be treated is looped, a draw-ofi' drum frictionally connected to said roller and of greater diameter than said roller, and means for rotating the roller and through it the drum, substantially as described.

In testimon whereof I afiix my signature in presence 0 two Witnesses.

FRIEDRICH JACOB MARTIN HANSEN. 

